A new report says that the world will need to more than double food production over the next 40 years to feed an expanding global population. But as the world’s food needs are rapidly increasing, the planet’s capacity to produce food confronts increasing constraints from overlapping crises that, if left unchecked, could lead to billions facing hunger.

The UN projects that global population will grow from today’s 7 billion to 9.3 billion by mid-century. According to the report released last week by the World Resources Institute (WRI), “available worldwide food calories will need to increase by about 60 percent from 2006 levels” to ensure an adequate diet for this larger population. At current rates of food loss and waste, by 2050 the gap between average daily dietary requirements and available food would approximate “more than 900 calories (kcal) per person per day.”

The report identifies a complex, interconnected web of environmental factors at the root of this challenge – many of them generated by industrial agriculture itself. About 24% of greenhouse gas emissions come from agriculture, encompassing methane from livestock, nitrous oxide from fertilisers, carbon dioxide from onsite machinery and fertiliser production, and land use change.

Industrial agriculture, the report finds, is a major contributor to climate change which, in turn is triggering more intense “heat waves, flooding and shifting precipitation patterns”, with “adverse consequences for global crop yields.”

Indeed, global agriculture is heavily water intensive, accounting for 70 per cent of all freshwater use. The nutrient run off from farm fields can create “dead zones” and “degrade coastal waters around the world”, and as climate change contributes to increased water stress in crop-growing regions, food production will suffer further.

Other related factors will also kick in, warns the report: deforestation from regional drying and warming, the effect of rising sea levels on cropland productivity in coastal regions, and growing water demand from larger populations.